Vacuum-tube circuit



VACUUM TUBE CIRCUIT Filed March 17, 1925 E Q E 66K?) @JULI/ wf-L 3\ v2g@ /VVVW nu w Mishima uw 555%@ @am LQ/1g@ n lli atented et.. i9, 19126.

PATENT OFFICE.'

anniv 1v. waaraan', onnasr ORANGE, ,NEW JERSEY, AssIeNon TonAnIornneUnNoY \LABORATORIES, ING., -A CORPORATION 0F NEW JERSEY.

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Applicatioiiiled March 17, 1925. Serial No.. 16,092; y

'lhe primary object. of this invention is to stabilize 'the electricalconditionsl in a vacuum tube in such manner that the grid will beaffected solely by the incoming radio wave impressed thereon," and toe1iminate distortions caused byelectrical strains set up fromothersource.s,' such as otentialvariations at the plate. Further o jectsand advantages of the invention, however, will be in part obviousand inpart specifically referred to in the description hereinafter contained,which taken in connection with the accompanying dra-wings, discloses theprinciples'of the'invention as applied to the circuits of a radibreceiving system. ln the drawingsw'lhe single figure is a diagrammaticvie'w of a radio receiving system adapted to func# tion inaccordancewith the invention.

lt should be understood that the present disclosure is merely typical asregards the receiver as a whole and the latter accordingly will notdescribed in detail, except .asregards' the particular features thereofwhich have-to do with the present invention. AI have found that thecurrent leaving the grid can be controlled by taking the fila'- K mentleads through a coil of the same inductance as that which is`connectedto the plate in such a way ythat the electrical strain produced at theend of one inductan'ce is counteracted by anl opposite and equal strainat the end of the other inductance.

.- Furthermore by magnetically coupling. the

indu'ctances above mentioned, the electrical strain from the plate tothe grid will be counteracted by the strain from the grid to thefilament, thereby preventing a current flow from the grid in the gridcircuit. In.

late or filament will not.`

othe words the reac upon the grld, regardless of what the tubecapacities are, and the tube will .therefore give true amplificationthroughoutits heating of the filament.

are cumulative for the radio current.

placed by a singlecoil included ductanceB. reviously mentioned.` Theinductance to e employed in coils 3, 6 and 7 is not at-.all critical solong as the resistance thereby interposed in the filament circuit is notso large as .to interfere with proper It will be noted that the coils 6and 7 are so relatedand connected in ycircuit as to counteract eachother asregards the A battery current but In some instances the coils 6and 7 maybe rein the nega tive filament lead.

The inductances 3a, 6l and ond tube.2 function in the manner abovedescribed andare similarly related. While -the coils 3b, 6", and 7b oftube 3 lin the 'next stage of amplification, and the coils 3, 3d,6 and7? of the tube 4 of the last stage, function in the samemanner, both areconnected .and related in a somewhat modified way on account of thedifferent circuit conditions under which they operate. f

lt will be noted that the inducta'nces are so connectedthat anyA;batteryvoltage variations will be neutralized and that the filamentpotential as regards the grid and plate ywill be held at anintermedia-te value.

Furthermore since under the. conditions above setforth no out of phasecurrent-s will be'produced,l it is possible to polarize the transformercoils in such a way that the magnetic interference between them will beaminimum.

While the invention has been disclosed as applied to certain particularcircuits it will beobvious that'many changes may be made therein withoutdeparting from its princifles as set forth in the appended claims.

claim:

1. A system of` electrical circuits includ.l

ing a three electrode vacuum tube, having means for preventing reactionsfrom the plate filament circuit back onto the grid I comprisinginductances in the plate and filament leads balan'cilg strains from theplate to the'grid by those from the filament to the grid..

2. A system of electrical circuits includ -ing athree electrode vacuumtube and means forpreventing reactions from the plate filament circuitback onto the grid, wherein the filament leads includesubstantially-,equal in- .ductance's, and the plate lead also includesinductance cooperating therewith to balance strains from the pla'te tothe grid by those from the lament to the grid.y

3. A system of electrical circuits'including a three electrode vacuumtube and means for preventing reactions from the plate lilainent circuitback onto ythe grid, lwherein the plate circuit includes an/inductauceand the lilament circuit includes-a counterbalancing inductanceof'substantially equal value.

4. A system of electrical circuits ,including a three electrode vacuumtube and means for preventing reactions from the plate filament circuitback onto the grid, wherein the plate circuit includes an inductance andthe lilamentfcircuit includes a counterbalancing inductance ofsubstantially equal value, said inductances being -magnetically'coupled. l

5; A system of electricall circuits, comprising successive stages eachincluding a threev electrode vacuum tube and With magnetic couplingsbetween stages, means 1n said stages for balancing strains from grid toplatefby those from Lgrid .to lament, "said means forming a part of themagnetic couplings aforesaid the secondary of one coup-j ling being soconnected to the succeeding stage as to polarize the primary of thesecond stage with respect to the primary of the .first stage.

6. A system ofielectrical circuits includ-- ing a three electrode vacuumtube and means for preventingreacticns from the plate filament circuitback ontothe grid, wherein the lilament leads include substantiallyequal inductances, and the plate lead J also includes inductancecooperating therewith to balance strains from the plate to the grid bythose from the filament to the grid,

said first mentioned inductances being magnetically coupled.

ment leads balancing strains from the plate fto the grid by those fromthe filament to the grid, said inductances being'magnetically coupled. i

In testimony that I claim the foregoing, I have hereunto set my handthis 10th day of March,` 1925. n

JOHN N. VARREN.

